A common type of carrier often used to package twelve or twenty-four beverage cans is the sleeve-type carrier. Such a carrier completely encloses the cans and is typically formed from a generally rectangular paperboard production blank which has been folded and glued by the blank manufacturer to form an interim sleeve-like product consiting of connected top, bottom and side panels. This interim product is shipped in flat collapsed form to the bottler who, through use of an automatic packaging machine, opens the semi-formed blank into its sleeve shape, inserts the cans into the sleeve and forms the end panels by gluing together flaps which are foldably connected to the blank.
After being fed to the packaging machine the collapsed blanks are partially opened while being delivered to a pocket formed between adjacent flight bars attached to moving endless chains. The blank opening process is completed in the pocket as the pocket moves with the chains to the container loading station.
This arrangement has several disadvantages. It is sometimes difficult to open the collapsed blanks after they have been stored for any length of time between their manufacture and their introduction to the packaging machine. The weight of the stacked blanks tends to press the opposed faces of a blank together to such an extent that they become difficult to separate, thus making it difficult for the packaging machine to open the collapsed blanks into sleeve form. In addition, when the blanks are stored under humid conditions they often warp, which tends to inhibit the ability of the passive blank opening guides to open the blank. Further, the process of opening or completing the opening of a blank while the blank is in the pocket between flight bars requires a considerable amount of working space, requiring the flight bars to be spaced a relatively great distance apart. This makes it necessary to run the flight bar chains at higher speeds than would normally be preferred in order to maintain packaging speeds consistent with the high speeds at which beverage containers can be delivered to the loading station. It would thus be beneficial to reduce the size of the flight bar pockets and to have a more positive carton opening means which is capable of overcoming the difficulties in opening warped or compressed blanks.